Standard law enforcement hiring process. Requires a written test, background check, physical, physical agility, psychological exam and interview. They now also require a polygraph test.
These law enforcement testing processes usually favor people who do well in the oral interview. People who know police officers tend to perform well on the oral interview portion of the test because there are standard questions most departments use. They may change the question based on current trends in law enforcement but there are standard answers they are looking for.
Expect some type of ethics question. Something like your partner steals something, is drinking at work, your partner assaults a suspect without justification. They always want to hear you will tell on the person. Never cover for anyone. But you need to elaborate, possibly ask some questions before you report the incident to make sure you did not see something and make an assumption without the facts, then report the incident.
Questions about working with the community are common as is the softball question of why do you want to work here or what would make you a good candidate for this position. This is where you have to brag about yourself and sell yourself and any community activities or leadership qualities.
Typically you will get some type of problem solving question. A report of burglary and a rape come in at the same time which call do you respond to first. Obviously the rape takes priority over the property crime.
Go to the departments website and read the mission statement, how many employees and the division in the department and work that information into you answers if possible.
I sat on a number of hiring boards and those are the things that got a lot of people hired.